Production of hydroxyether amides of polyacrylic acid



United States atent 2,808,397 Patented Oct. 1, 1957 PRODUCTION OFHYDROXYETHER AMIDES F POLYACRYLIC ACID N0 Drawing. Application February16, 1953, Serial No. 337,218

Claims priority, application Germany February 23, 1952 6 Claims. (Cl.260-89.7)

The present invention relates to a process of producing hydroxyetheramides of polyacrylic acid.

It is known to produce surface-active products by hydroxyalkylation offatty acid amides (German Patent 667,744). Furthermore, it is known toprepare polymers by polymerizing hydroxyamides of acrylic acid. Suchpolymers may be employed for instance as assistants in the textileindustry (French Patent 885,738).

It is an object of the present invention to provide a novel andconvenient process of producing hydroxyether amides of polyacrylic acid.According to the invention this is effected by reacting polyacrylamide,or an N-substitution product thereof having one free hydrogen atom or atleast one hydroxyalkyl radical attached to the nitrogen atom, with analkylene oxide or functional derivative thereof such as a halohydrin ora.a-halogeno-hydroxyether, if necessary in the presence of abasic-reacting substance.

By means of this reaction hydroxyether groups are introduced intopolyacrylamide or polymers of substituted acrylamides in which a freehydrogen atom or hydroxyalkyl group is attached to the nitrogen atom,for example acrylic acid ethyl amide.

It was not to be foreseen by one skilled in the art thathydroxyalkylation could be applied to polymers such as those of theamides of acrylic acid.

The reaction is preferably carried out by dissolving polyacrylamide in asuitable solvent, for example water, and introducing an alkylene oxide,for example ethylene oxide, into the solution under pressure afteraddition of a catalyst. Basic reacting substances such as hydroxides andalcoholates of alkali metals, and surface-active materials such asFullers earth, have proved particularly suitable catalysts. The quantityof the alkylene oxide to be added varies within wide limits and dependsupon the properties desired in the end product.

Apart from the reaction of alkylene oxides upon polyacrylamides in thepresence of catalysts, there is a further embodiment of the process ofthe invention which consists in reacting polyacrylamide witha.a'-halogeno-hydroxyothers, for instance halohydrins of polyglycols ofthe general formula:

X.CH2.CH2.(OCH2.CH2)11.OH

wherein X is a halogen atom and n is an integer of at least 1.

To bind the hydrogen halide which is set free in this reaction theprocess is preferably carried out in the presence of alkali metalhydroxides or carbonates.

Apart from polymers of acrylamides, copolymers of acrylamides and otherpolymerizable compounds such as acrylates, acrylonitrile and vinylacetate, are amenable to the reaction. The use of these copolymersenables prod- 2 ucts to be obtained having properties which can bevaried within wide limits.

The products obtained by the above described process are valuableauxiliary agents for the pharmaceutical industry and for plantprotection.

The invention is further illustrated by the following ex ample in whichthe parts given are by weight.

Example 175 parts of an aqueous solution of polyacrylamide (11 percent)is mixed with 3 parts of N caustic soda solution and reacted with 200parts of ethylene oxide at C. in an autoclave. It is preferable to addthe ethylene oxide in successive portions and to delay the addition of afresh portion of ethylene oxide until the portion last added hassubstantially been consumed, which can easily be determined by observingthe decrease in pressure. The reaction product thus obtained is aviscous liquid.

We claim:

1. A process for the production of viscous aqueous solutions ofwater-soluble N-substituted homopolyacrylamides, said N-substituentsbeing those of the formula -RtO-R)nOH, wherein R is the alkylene residueof an alpha, beta-alkylene epoxide and n is an integer of at least 1which comprises reacting, in aqueous solution and at elevatedtemperature, water-soluble polyacrylamide having at least one hydrogenatom attached to the nitrogen atom with a lower alkylene oxide.

2. A process for the production of viscous aqueous solutions ofWater-soluble N-substituted homopolyacrylamides, said N-substituentsbeing those of the formula -RtO-R-)1LOH, wherein R is the alkyleneresidue of an alpha, beta-alkylene epoxide and n is an integer of atleast 1 which comprises reacting, in aqueous solution and at elevatedtemperature, wate -soluble polyacrylamide having at least one hydrogenatom attached to the nitrogen atom with a lower alkylene oxide in thepresence of a basic reacting substance.

3. A process for the production of viscous aqueous solutions ofwater-soluble N-substituted homopolyacrylamides, said N-substituentsbeing those of the formula R{-OR-}nOI-I, wherein R is the alkyleneresidue of an alpha, beta-alkylene epoxide and n is an integer of atleast 1 which comprises reacting, in aqueous solution and at elevatedtemperature, water-soluble polyacrylamide having at least one hydrogenatom attached to the nitrogen atom with a halohydrin of the generalformula:

wherein X is a halogen atom and n is an integer of at least 1.

4. A process for the production of viscous aqueous solutions ofWater-soluble N-substituted homopolyacrylamides, said N-substituentsbeing those of the formula -R{-OR%LOH, wherein R is the alkylene residueof an alpha, beta-alkylene epoxide and n is an integer of at least 1which comprises reacting, in aqueous solution and at elevatedtemperature, Water-soluble polyacrylamide having at least one hydrogenatom attached to the nitrogen atom with a halohydrin of the generalformula:

wherein X is a halogen atom and n is an integer of at least 1 in thepresence of a basic reacting substance.

5. Water-soluble N-substituted homopolyacrylamides, said N-substituentsbeing those of the formula 0 wherein R is the alkylene residue of ana1pha,beta-a1ky1- ene epoxide and n is an integer of at Least. 1.

6. Water-soluble N-substituted homopolyacrylamides, said N-substituentsbeing those of the formula -CH2CHz(-OCHzCHz-)11OH wherein it is aninteger of at least 1.

References Cited in the file of this patent UNITED STATES PATENTSFikentscher et al. Oct. 9, 1934 Arnold July 30, 1946 Thurston et a1 May10, 1949 Jones Dec. 5, 1950

1. A PROCESS FOR THE PRODUCTION OF VISCOUS AQUEOUS SOLUTIONS OFWATE-SOLUBLE N-SUBSTITUTED HOMOPOLYACRYLAMIDES, SAID N-SUBSTITUENTSBEING THOSE OF THE FORMULA -R(-O-R-)NOH, WHEREIN R IS THE ALKYLENERESIDUE OF AN ALPHA, BETA-ALKYLENE EPOXIDE AND N IS AN INTEGER OF ATLEAST 1 WHICH COMPRISES REACTING, IN AQUEOUS SOLUTION AND AT ELEVATEDTEMPERATURE, WATER-SOLUBLE POLYACRYLAMIDE HAVING AT LEAST ONEHYDROGENATOM ATTACHED TO THE NITROGEN ATOM WITH A LOWER ALKYLENE OXIDE.